Radial pump or motor



July 14, 1942.

E. K. BENEDEK RADIAL PUMP OR MOTOR Filed Nov. 6, 1940 6 Sheets-Sheet l WW Wmv w W W N I `w QQ Nm.v mm.. .Q ww W QQ wv \\\mmv m @N Q QN uw -www Jmm, l .Nm A@ A ww. @www mm v www @m ww ww mw kwh@ ww Q QH .E ma@ o mw www .mmv mw l QW WMM@ w. w N NQ QQ mw" avv k im, w N mw QQ um Q m, .Immm

gmc/whom Elek enedek July 14, 1942. E. K. BENEDEK RADIAL PUMP OR MOTOR Filed Nov. 6, 1940 6 Sheets-Sheet 2 SM. uw. L k 7 Z mw @Wa E QW N d m m@ W w bv Y mw Sw @uw WMU K M @4% k we@ #e M N o @MU NH o ma NIT @mw o wm ww. TH www w o o m mw vw uw mm 1W www /H Nmwwr July 14, 1942. E. K. BENEDEK RADIAL PUMP OR MOTOR Filed Nov. 6, 1940 6 Sheets-Sheet 5 Elek' K. .Benedek July 14, 1942. E K, BENEDEK 2,289,866

RADIAL PUMP OR MOTOR Filed Nov. 6, 1940 6 Sheets-Sheet 4 July 14, 1942. E. K. BENEDEK RADIAL PUMP OR MOTOR Filed Nov. 6, 1940 6 Sheets-Sheet 5 aw ,L W k Z/ ////4 m Haw LW 2 ww wm NQ. 32 e w m www \mw m V mm kw.- K, Sw M J No o ...N a Sw a mm wm o Nvxmm, QW o No O u@ Y w @n July 14, 1942. E. K. BENEDEK RADIAL PUMP 0R MOTOR 6 Sheets-Sheet 6 Filed Nov. 65, 1940 'Patented July 14, 1942 zasasss oFFIcE RADIAL PUMP on Moron Elek K. Benedek, Cleveland, Ohio, assignor, 4'by assignments. to Midland Machine Corporation, a corporation of Illinois Application November 6, 1940, Serial No. 364,585

This invention relates to hydraulic pumps or motors, and more particularly to hydraulic pumps spaced cylinders adapted to have valved communication with the pintle conduits, pistons in the cylinders, and means for effecting reciprocation of the pistons relatively to the respective cylinders when the cylinder barrel is rotated. Because of their substantially continuous, positive pressure discharge characteristics, such pumps lately have found Wide application in various fields, use for driving machine tools and hydraulic presses being representative examples of useful applications.

Pumps of this general class heretofore proposed most commonly have included a single set of circumferentially deployed radial piston and cylinder assemblies. For such machines to deliver iiuid at high volumetric rates without operating at prohibitive speeds, it has been necessary to use large pistons and cylinders, increasing the diameter of the rotating assemblies and surrounding I parts so that inordinate centrifugal forces have been produced, resulting in high thrust bearing pressures and rapid wear, and'necessitating inconveniently large overall radial dimensions.

To overcome these difficulties it heretofore has been proposed to provide a plurality, e. g., two sets of piston and cylinder assemblies spaced from each other longitudinally of the pump pintle and to operate the pistons in pairs, each pair including do with improvements in the construction and vassembling of pumps or motors of this'particular kind.

pump or motor of the class referred to in which the construction and relative arrangement of the parts enables the incorporationl in a compact machine of a plurality of sets of spaced piston and cylinder assemblies.

Another object is to provide a pump or motor An object of thel invention is to provide a i 2li Claims. (Cl. 103-161) to facilitate manufacturing and assembling of the parts. Y v

Another object is to provide simple and effi-- cient means for transmitting thrust to the reciprocable elements of the piston and cylinder assemblies. o A further object is to provide a compact and durable organization of parts for transmitting thrust to pistons of two spaced sets of piston and cylinder assemblies in which the assemblies of one of the sets are staggered circumferentially with respect to the assemblies of the other set. Other objects will become apparent from a reading of the following detailed description, the appended claims and the accompanying drawing in which:

' Figure 1 is a longitudinal horizontal sectional View of a pump'or .motor embodying the invention, the section being taken on the line l-l ofl Figure'2;

FigureZ is a transverse vertical sectional view taken on the line 2--2 of Figure 1;

Figure 3`is a fragmentary sectional view taken on the line 3--3 of Figure 1;

Figure 4`is a detailed sectional viewtaken on Figure 10 is a fragmentary developed sectional view taken Figure 8.

The embodiment disclosed in Figures 1 to 6, inclusive, comprises a casing I including two end plate sections 2 and 3 and an intervening ring section I secured between the end plate sections on the curved line Ill-'I0 of 'by means of screws 5. The opposed inner faces 0f the peripheral portions of the end plates 2 and 3 are recessed to provide shoulders li and 1 which serve accurately to locate the end plates Q2 and 3 and the ring member 4 in assembled relation. A .hardened stationary pintle 9 has a press t in a bore I0 formedin an axial hublike extension' Il of the end lplate section`2. The pintle is formed with a .reduced diameter portion I2 on which a cylinder barrelvunit generally designatedV I3` is journaled by roller bearings I4 of the character stated ofgsuch construction as for rotation about the pintle axis. The end plate section 3jis formed with a hub extension I5 in which is mounted an anti-friction ball bearing assembly generally designated I6, the outer race I1 of whichfis held in place by an end cap Il secured to the hub portion l5 by screws I9. The inner race of the bearing assembly I6 is mounted on an inner end portion 2| of a drive shaft generally designated 22. At the extreme inner end of the shaft 2| is an enlarged ilange 23 providing a shoulder 24 against which the inner ball race 20 is clamped by a nut 25 engaging a threaded portion 26 of the shaft 22. The shaft flange 23 is secured to -the cylinder barrel by means of screws 21. The shaft 22 may be used to impart positive driving effort to the cylinder barrel unit I3 if the machine is to be used as a pump,'and may be used to transmit power from the rotating cylinder barrel unit I3 to external apparatus to be driven when the machine is to be used as a hydraulic motor. To facilitate manufacturing and assembling of the machine, the cylinder barrel unit |3 is formed in two axially separable sections 26 and 28 having a mortise Joint as at 29v and being secured together by bolts 30.

The cylinder barrel unit is formed with two axially spaced sets, generally designated A and B, of radially disposed, circumferentially deployed, piston and cylinder assemblies. The set A of piston and cylinder assemblies, shown at the right in Figure 1 and also shown in Figure 2, includes a plurality of circumferentially spaced cylinders 3| formed in the cylinder barrel section 23 and respectively communicating with ports 32 in turn adapted to have valved communication with pintle cut-outs or ports 33 having constant communication with bored pintle passages 34. The passages 34 communicate with combined inlet and outlet openings on opposite sides of the pintle and one, 35, of which is shown at the left in Figure l. Pistons 36 are mounted respectively for reciprocation in the cylinders 3|.

When the cylinder barrel and pistons are rotated, the pistons will be reciprocated relatively to the associated cylinders in a manner to be described later, and the valved intake and discharge of uid through the opening 35, the passages 34, the cut-out ports 33, and the cylinder end ports 32 will take place in a manner well understood in the art. The other set B of piston and cylinder assemblies' is spaced axially to the left (as viewed in Figure 1) of the set A and includes a plurality of cylinders 3|' formed in the cylinder barrel section 28 and in which pistons 35' are mounted for reciprocation to take in and discharge fluid through end ports 32', pintle cutout passages 33', the bored pintle passages 34, and the pintle intake and outlet openings 35.

Individual piston and cylinder assemblies of the set A are paired, respectively, in parallelism with individual piston and cylinder assemblies of the set B, and means are provided for reciprocating the paired pistons of the two sets in unison. 'I'he pistons 35 of the set A are formed with crossheads 31 mounted to slide in guides formed in a flange 38 integral with the cylinder barrel section 28. Similarly, the pistons 3,6 of the set B are formed with crossheads 31' slidable in guides formed in a flange 38 integral with the cylinder barrel section 28. The crossheads 31 and 31' of the sets Aand B are paired, and are formed respectively with bores equipped with` bushings 39-39.' Thrust-transmitting cross pins 40 and 46|' are journaled respectively in the bushings 33 and 39'. Pins v40 and 40' associated respectively with paired pistons of the sets A and B are aligned with their inner ends in face-to-face relation and are held in' place by retaining rings 4| and 4 I For transmitting thrust to and reciprocating the pins and the pistons of both sets A and B, reactance means surrounding the piston 'and cylinder assemblies of both sets A and B is provided with annular tracks engaged by the pins in three zones spaced from each other longitudinally of the pintle axis; and means are provided for mounting the three tracks of the reactance means eccentrically with respect to the pintle axis, so that, as the cylinder barrel, the pistons, and the pins rotate about the pintle axis, the engagement of the pins simultaneously with the three eccentrically disposed tracks will move the pistons in to their respectively associated cylinders. The reactance means includes a shiftable, non-rotating reactance stator comprising end sections 42 and 42' secured to a central ring section 43 by means of screws 44-44'. The ring section 43 is formed with flat pads 45 mounted to slide on pads 46 formed on the inner surface of the casing ring 4 so as to mount the stator for shifting movement to vary its eccentricity with respect to the pintle axis. Rods 41 secured to the central ring section 43 of the stator extend through the casing and are adapted to be connected to suitable handles or mechanism for shifting the stator. It is usual to mount the reactance stator in pumps of this class so that it may shift to vary its eccentrlcity, and, hence, the rate of discharge of the pump, but it will be understood that the invention may be embodied in rotary radial pumps wherein the reactance stator is mounted in a xed eccentric position.

The stator end sections 42 and 42' are formed, respectively, with bearing race seats 48 and 48' which respectively receive the outer races of bearing assemblies generally designated 49 and 49'. 'I'he bearing assemblies 49 and 49' serve antifrictionally to mount a rotary reactance member 50 comprising end plate sections 5| and 5| secured by screws 52 and 52', respectively, to a hardened central ring section 53.

The end plate sections 5| and 5|' are formed respectively with annular tracks 54 and 54 disposed in the radial planes or zones of the outer end of the pins 40 and 40. Outwardly beyond the tracks 54 and 54 the end plate sections 5| and 5|" are formed, respectively, with outer radial surfaces 55 and 55' which lie alongside and serve to guide the outer portions of the crossheads 31 and 31. Inwardly of the annular tracks 54 and 54 the end plate sections 5| and 5| are formed, respectively, with inner radial surfaces 56 and 56 which lie alongside the extreme end portions of the pins 40-40 with working clearance between the radial surfaces and the iiat pin ends. The central section 53 of the rotary reactance 50 is formed with an inwardly extending, centrally disposed flange 51 located between the radial planes of the sets A and B. The inner face of the flange 51 constitutes a track 58 upon which the inner ends of the pins 40-40' are adapted to roll. Opposed, outwardly directed, radial faces 59 and 59' of the track flange 51 lie alongside and respectively guide the outer portions of the piston crossheads 31 and 31.

When the machine is operated as a pump, the centrifugal force acting on the pins 46-4|l', pistons 36 and 36', and associated crossheads tends to move them outwardly with respect to their cylinders so as to perform suction strokes. `To

assist in this outward movement, and, more parv :i-tficularly, to maintain the pins in engagement with *the reactance tracks 58, 54, and 54 when the pump is at rest and 'whileit is being brought up to operating speed, floating return-thrust-transouter end portions of the pins 40-40'. Thevrings I and 60 are supported radially solely by their engagementwith the pins lli-40', and are con- `flned against movement longitudinally of the piston by the piston crossheads and the adjacent 40-40'. It is held against shifting axially of the pintle by engagement with adjacent faces of the crossheads 31 and 31'.

In operation, when the reactance stator and the rotary reactance member 50 carried thereby are shifted to lbe eccentric to the pintle axis, rotation of the cylinder barrel, the pistons of both sets A and B, and thepins will cause the pins 40-40' to roll in three zones on the tracks 54, 54', and 58; and the pins and the `pistons of both sets A and B will be reciprocated radially to effect valved intake and discharge of fluid through the ports and passages previously described.

The parts of the simple andrugged construction described above are adapted for economical manufacture 'and quick assembling and disassembling for cleaning or servicing. The simple thrust-transmitting pins of uniform diameter can be made from bar or tube stock` and finished in mass production by centerless grinding.

In the modified embodiment shown in Figures 7 to 10,` inclusive, the construction is gen'- erally similar to that described above. It differs specifically therefrom only as is described below, it being understood that parts of the modified form not specifically referred to are essentially the same as corresponding parts of the embodiment shown in Figures 1` to 6, inclusive.

In the modified embodiment the sets A and B of piston and cylinder assembliesA are staggered circumferentially with respect to each other so as to permit the pins 40 of the section A to overla'p respectively and intervene between adjacent pins 40' of the section B between the sets A and B. This makes it possible to decrease the width of the reactance rotor indicated generally at 50. The rotor comprises end sections 5i and 5I which are the same as the corresponding sections in` the reactance rotor shown in Figures 1 to 6, inclusive, and a central .ring section 53 interposed between the end sections 5I and 5I'.

, 'Ihe central ring section 53a is narrower than the Figures 1 to 6, inclusive, with the exception that the staggering 0f the sets of piston and cylinder assemblies makes for a more 'uniform`fiow of fluid with consequent lessening of the magnitude of pulsations and 4for more even distribution of the piston load about the periphery of the reactance.

'I'he construction shown herein for the purposes of illustration embody the invention in its4 now preferred forms, but it will be apparent that some changes'in the construction and relative arrangement of the parts may be made .without departing from the invention .as defined in the claims.

I claim:

1. In a rotary hydraulic pump or motor, two

sets\ of rotatable radial piston and cylinder assemblies, each set including a plurality of circumferentially deployed piston and cylinder assemblies, said assemblies each comprising a piston element and acooperating cylinder element, one element of each assembly being reciprocable radially relative to the axis of rotation of said assemblies and said sets of assemblies being spaced from each other longitudinally of the axis of r0- tation; thrust-transmitting pins respectively individually journalled in the reciprocable elements of both 'sets and extending parallel to said axis of rotation, the pins journaled in the reciprocable elements of one set being independent of the pins journaled in the reciprocable elements of theother set; and a reactance member for effecting reciprocation of all said reciprocable elements in response to rotation of said assemblies, said reactance member including a track eccentric to said axis of rotation, being located between said sets of assemblies, and being rollingly and independently engaged by all of said pins of both said sets of assemblies.

2. In a rotaryhydraullc pump or motor, two I sets of rotatable radial piston and cylinder assemblies, each set including a plurality of circumferentially deployed piston and cylinder assemblies, said assemblies each comprising a piston element and a cooperating cylinder element, one element of each assembly being reciprocable radially relative tothe axis of rotation of said spectively associated reciprocable elements, the

, pins. journaled in the reci-procable .elements of y ton element and a cooperating cylinder element one set being independent of the pins journaled in the reciprocable elements of the other set; and a reactance member for effecting reciprocation of all said reciprocable elements in response to rotation of said assemblies, said reactance member including a track eccentricto said axis of rotation, being located between said sets of assemblies, and being rollingly and independently .engaged lay-projecting portions of all of said pins of 'both said sets of assemblies.

3. In a rotary hydraulic pump or motor, two sets of rotatable radial piston and cylinder assemblies, each set including a plurality of circumferentially deployed piston and cylinder assemblies, said assemblies each comprising a pisone element of each assembly being reciprocable radially relative to the axis of rotation of said assemblies and said sets of assemblies being spaced fromeach other longitudinally of the axis of rotation, thrust-transmitting pins respectively individually journaled in the reciprocable elements of both sets and extending parallel to said axis of rotation and projecting beyond the respectively associated reciprocable elements, the

` pins journaled in the reciprocable elements of one set being independent of the pins journaled in 'the reciprocable elements of the other set; and

a reactance member for effecting reciprocation of all said reciprocable elements in response to rotation of said assemblies, said reactance member including a track intervening said two sets of piston and cylinder assemblies and being eccentric to said axis of rotation, said track being rollingly and independently engaged by projecting portions of all of said pins of both saidl sets of assemblies.

4. In a rotary hydraulic pump or motor, two sets of rotatable radial piston and cylinder assemblies, each set including a plurality of circumferentially deployed piston and cylinder assemblies, said assemblies each comprising a piston element and a cooperating cylinder element, one element of each assembly being reciprocable radially relative to the axis of rotation of said assemblies and4 said sets of assemblies being spaced from each other longitudinally of the axis of rotation; thrust-transmitting pins respectively individually journaled in the reciprocable elements of both sets and extending parallel to said axis of rotation and projecting beyond the respectively associated reciprocable elements, the lpins journaled in the reciprocable elements of one set being independent of the pins journaled in the reciprocable elements of the other set; and a reactance member for effecting reciprocation of all said reciprocable elements in response to rotation of said assemblies, said reactance member including a single continuous track intervening said two sets of piston and cylinder assemblies and being eccentric to said axis of rotation, said track being rollingly and independently engaged by projecting portions of all of said pins of both said sets of assemblies.

5. In a rotary hydraulic pump or motor, two sets of rotatable radial piston and cylinder assemblies, each set including a plurality of circumferentially deployed piston and cylinder assemblies, said assemblies each comprising a piston element and a cooperating cylinder element, one element of each assembly being reciprocable radially relative to the axis 0f rotation of said assemblies and said sets of assemblies being spaced from each other longitudinally of the axis of rotation; thrust-transmitting pins respectively individually journaled in the reciprocable elements of both sets and extending parallel to said axis of rotation, said pins respectively having opposite end portions projecting beyond their associated reciprocable elements, the pins journaled in the reciprocable elements of one set being independent of the pins journaled in the reciprocable elements of the other set; and a reactance member for effecting reciprocation of all said reciprocable elements in response to rotation o1' said assemblies, 'said reactance member including three spaced tracks similarly eccentric to said axis of rotation, the middle track intervening said sets of assemblies' and being rollingly and independently and simultaneously engaged by projecting portions of said pins of both said sets of assemblies which extend between said sets of assemblies, one of the end tracks being rollingly and simultaneously engaged by the other pro jecting portions of pins associated with one set of assemblies and the other end track being rollingly and `simultaneously engaged by the other projecting portions of pins associated with the other set of assemblies.

6. In a rotary hydraulic pump or motor, two sets of rotatable radial piston andcylinder assemblies, each set including a plurality of circumferentially deployed piston and cylinder assemblies, said assemblies each comprising a piston element and a cooperating cylinder element, one element of each assembly being reciprocable radially relative to the axis of rotation of said assemblies and said sets of assemblies being spaced from each other longitudinally of the axis of rotation; thrust-transmitting pins respectively individually journaled in the reciprocable elements of both sets and extending parallel to said axis of rotation and projecting beyond the respectively associated reciprocable elements, the pins journaled in the reciprocable elements of one set being independent of the pins journaled in the reciprocable elements of the other set; and reactance means for-effecting reciprocation of all said reciprocable elements in response to rotation of said assemblies, said reactance means including a relatively xed working-thrust transmitting track eccentric to said axis of rotation and being rollingly and independently engaged by projecting portions of all said pins of both said sets of assemblies, and a relatively floating ringv providing a suction-thrust transmitting track also rollingly engaged by the same projecting portions of said pins, both said tracks being disposed between said sets of assemblies.

7. In a rotary hydraulic pump or motor, a l

rotatable cylinder barrel unit comprising two sections adapted to be assembled and separated in a direction longitudinally of the axis of rotation of said unit, and means for maintaining said sections in assembled relation, each section being formed with a set of radial, circumferentially deployed cylinders, the two sets of cylinders being mutually spaced longitudinally of said axis of rotation; pistons reciprocable in the cylinders of each set respectively; thrust-transmitting pins respectively individually journaled in the pistons associated with each set of cylinders and extending parallel to said axis of rotation and projecting beyond the respectively associated pistons, the pins journaled in the pistons of one set being independent of the pins journaled in the pistons of the other set; and a reactance member for effecting reciprocation of all said pistons in response to rotation of said cylinder barrel, said reactance member including a track intervening said two sets of pistons and being eccentric to said axis of rotation, said track being rollingly and independently engageable by projecting portions of said pins of both said sets of pistons.

8. In a rotary hydraulic pump ormotor, a rotatable cylinder barrel unit comprising two sections adapted to be assembled and separated in a direction longitudinally of the axis of rotation of said unit, means providing a mortise joint between said sections for aligning them, and means for maintaining said sections in assembled relation, each section being formed with a set of radial, circumferentially deployed cylinders, the

two sets of cylinders being mutually spaced longitudinally of said axis of rotation; pistons reciprocable in the cylinders of each set respectively; thrust-transmitting pins respectively individually journaled in the pistons associated with each set of cylinders and extending parallel to said axis of rotation and projecting beyond the respectively associated pistons, the pins journaled in the pistons of one set being independent of the pins journaled in the pistons of the other set; and a reactance member for effecting reciprocation of all said pistons in response to rotation of said cylinder barrel, said reactance member including a track intervening said two sets of pistons and being eccentric'to said axis of rotation, said track being rollingly and independently engageable by projecting portions o! said pins of both said sets o! pistons.

9. In a rotary hydraulic-pumpv or motor,two.

` axis of rotation, individual assemblies of one of said sets being paired respectively in parallelism with individual assemblies o! the .other of said sets; thrust-transmitting pins respectively individuallyjournaled in the reciprocable elements of both sets and extending parallel to said axis of rotation, the pins journaled in the reciprocable elements of one set being independent'oi the pins journaled in the reciprocable elements of the otherset; and a reactance member for eectins reciprocation of all said reciprocable elements in response to rotation of said assemblies, said reactance member including a track eccentric t said axis of` rotation and being rollingly and independently engaged by all o'f said pins of both said sets of assemblies. e o i 10. In a rotary hydraulic pump` or motor, two sets ofv rotatable radial piston and cylinder assemblies, each set including a plurality of circumferentially deployed piston` and cylinder assemblies, said assemblies each comprising aopiston element and a `cooperating cylinder element, one element of each assembly being reciprocable` radially relative to the axis of rotation of said naled in the reciprocable elements of oneset being independent of the pins journaled in the reciprocable elements of the other set; and a reactance member for ,eiIecting reclprocation of all said reciprocable elements in response to rotation of said assemblies, said reactance member including a track intervening said two sets of piston and cylinder assemblies and being eccentric to said axis of rotation, said track being rollingly and independently engaged by projecting portions of all of said pins of both said sets of assemblies.

12. I n a. rotary1 hydraulic'pump or motor, two sets of rotatable radial piston and cylinder assemblies', each set including a `plurality of -circumferentially deployed piston and cylinder assemf spaced from each other longitudinally of the axisof rotation, individual assemblies of one of said sets being paired respectively in parallelism with individual assemblies of the other of said sets;

thrust-transmitting pins respectively individually journaled in the reciprocable elements of both 'ciprocable elements in response to rotation oi' assemblies and said sets of assemblies being spaced from each other longitudinally of the axis actance member for effecting reciprocation `of all said reciprocable elements in response to rotation of said assemblies, said reactance member including a track eccentric to said axis of rotation and being rollingly and independently en,

gaged by projecting portions of of both said sets of assemblies.

l1. In` a rotary hydraulic pump or motor, two sets of rotatable radial piston and cylinder assemblies, eachset including a plurality of circumferentially deployed piston and cylinder asall of i said pins semblies, said assemblies each comprising a` piston element and a cooperating cylinder element, one element of each assembly being reciprocable l radiallyrelative to the axis of rotation of said assemblies and said sets of assemblies being spaced from each other longitudinally of the axis of rotation, individual assemblies of one of said sets being paired respectively in parallelism with individual assemblies of the other of said sets; thrust-transmitting pins respectively individually journaled in the reciprocable elements of both sets and extending parallel toy said' axis ofV rotation and projecting beyond the respectively associated reciprocable elements, the` pins joursaid assemblies, said reactance member including ,three spaced tracks similarly eccentric to said axis of rotation, the middle track intervening said sets of assemblies and being rollingly and independently and simultaneously engaged by projecting portions of said pins `which extend between said sets of assemblies, the. pins associated with the assemblies of each pair of assemblies being aligned with each other and being in end-to-end relation over said middle track, one of the end tracks being rollingly and simultaneously engaged by the-other projecting portions of pins associated with one set of assemblies and the other end track being rollingly and simultaneously engaged by the other projecting portions of pins associated with the other set of assemblies.

13. In a rotary hydraulic pump or motor, a rotatable cylinder barrel having formed therein two sets of. cylinders, each set comprising a plurality of radial, clrcumferentially deployed cylinders lying in a common plane transverse to the axis of rotation, the two sets being spaced from each other longitudinally of the axis of rotation of said barrel, individual cylinders of one of said sets being paired respectively in parallelism with individual cylinders of said other of said sets, thrust-transmitting pins respectively individually journaled in the pistons associated. with each set of cylinders and extending parallel to said axis of rotationy and projecting beyond the respectively associated pistons, the pins journaled in the pistons of one set being independent of the pins journaled in the pistons of the other set; and a reactance member for effecting reciprocation of all said pistons in response to rotation of said cylinder barrel, said reactance member including a track intervening said two sets pendently engageable by projecting portions oi" said pins of both said sets of pistons, the pins associated with the pistons of each pair of pistons being aligned with each other and being in assemblies and said sets of assemblies beingv spaced from each other longitudinally of the axis of rotation, the assemblies of one ofsaid sets being circumferentially staggered with respect to the assemblies of the other of said sets; thrusttransmitting pins respectively individually journaled in the reciprocable elements of both sets and extending parallel to said axis of rotation, the pins journaled in the reciprocable elements of one set being independent of the pins journaled in the reciprocable elements of the other set; and a reactance member for effecting reciprocation of all said reciprocable elements in response to rotation of said assemblies, said reactance member includingla track eccentric to said axis of rotation and being rollingly and independently engaged by all of said pins of both said sets of assemblies.

`15. In a rotary hydraulic pump or motor, two sets of rotatable radial piston and cylinder assemblies, each set including a plurality 'of circumferentially deployed piston and cylinder assemblies, said assemblies each comprising a piston element and a cooperating cylinderv element, one element of each assembly being reciprocable radially relative to the axis of rotation of said assemblies and said sets of assemblies being spaced from each other longitudinally of the axis of rotation, the assemblies of one of'said sets being circumferentially staggered with' respect to the assemblies of the other of said sets; thrust-,transmitting pins .respectively individually journaled in the reciprocable elements of and extending parallel-to said axis oi rotation and projecting beyond the respectively associated reciprocable elements, the pins journaled in the both sets and extending parallel to said axis of rotation and projecting beyond the respectively associated reciprocable elements, the pins journaled in the reciprocable elements of one set being independent of the pins journaled in the reciprocable elements `of the other set; and a reactance member for eilecting reciprocation of all said reciprocable elements in response to rotation oi' said assemblies, said reactance member including a track eccentric to said axis of rotation'and being rollingly and independently engaged by projecting portions of all of said pins oi both said sets of assemblies.

16. In a rotary hydraulic pump or motor, two

sets of rotatable radial piston and cylinder as semblies, each set including a plurality oi ciroumferentially deployed piston and cylinder assemblies, said assemblies each comprising a piston element and a cooperating cylinder element, one element of each assembly being reciprocable radially relative to the axis of rotation of said assemblies and said setsl of assemblies being spaced from each other longitudinally of the axis of rotation, the assemblies of one of said sets being circumferentially staggered with respect to the assemblies of the other of said sets; thrusttransmitting pins respectively individually jour- -naled in the reciprocable elements of both sets rotatable cylinder barrel'unit comprising two secreciprocable elements of one set being independent of thepins journaled in the reciprocable elements of the other set; and a reactance member for eftecting reciprocation of all said reciprocable elements in response to rotation oi' said assemblies, said reactance member including a track intervening said two sets o! piston and cylinder assemblies and being eccentric to said axis of rotation, said track being rollingly and independently engaged by 'projecting portions of all of said pins of both s aid sets of assemblies.

17. In a rotary hydraulic pump or motor, two sets of rotatable radial piston and cylinder assemblies, each set including a plurality oi' circumferentially deployed piston and cylinder assemblies, said assemblies each comprising a piston element and a cooperating Acylinder element, one-element of each assembly being reciprocable radially relative to the axis of rotation of said assemblies and said sets of assemblies being spaced from each other longitudinally of the axis of rotation, the assemblies of one of said sets being yeircumfere'ntiallyv staggered with respect to the assemblies of the other ot said sets. thrust-transmitting pins respectively individually journaled in the reciprocable elements of both sets and extending parallel to said axis of rotation, said pins respectively having opposite end portions projecting beyond their associatedreciprocable elements, the pins journaled in the reciprocable elements of one set being independent of the pins journaled in the reciprocable elements of the other set; and a reactance member for VeiIecting reciprocation of all said reciprocable blies, the pins associated with the assemblies of one'of said sets overlapping' the pins associated with the assemblies of said other set parallel to said axis of rotation, one of the end tracks being` rollingly and simultaneously engaged by the other projecting portions of pins associated with one set of assemblies and the other end track being rollingly and simultaneously engaged by the other projecting portions of pins associated with the other set of assemblies.

18. In a rotary hydraulic pump or motor, a

tions adapted torbe assembled and separatedv in a direction longitudinally ofthe axis of rotation of said unit, and means for maintaining said sections in assembled relation, each section being -formed with a set of radial, circumferentially deployed cylinders, the two sets of cylinders being mutually spaced longitudinally of said axis of rotation, the fcylinders of one of said sets being circumferentially staggered with respect to the cylinders of the other of `said sets; pistons reciprocable in the cylindersl of each set respectively and -ha'ving outer'end portionsprojecting radially outwardly beyond said cylinder barrel unit;a reactance assembly surrounding-said cylinder barrel unit and comprising a middle section and two end sections separably connected to said middle section, said middle section being `tric end tracks; and thrust-transmitting pins respectively individually journaled in the outer end said middle track and one of said end tracks, and

the projecting portions of the pins associated with the pistons of the other of said sets having roll- .ing engagement respectively with said middle track and the other of-said end tracks. o

19. In a rotaryfhydraulic pump or motor, a rotatable cylinder barrel unit comprising two sections adapted to be assembled and separated in a direction longitudinally of the axis of -rotation of said unit, and means for maintaining said sections in assembled relation, each section being formed with a set of radial, circumferentially deployed cylinders, the two sets of cylinders being mutually spaced longitudinally of said axis of rotation, `the cylinders of one of said sets being circumferentially staggered with respect to the cylinders of the other of said sets; pistons reciprocable in the cylinders of each set respec'- tively and having outer end portions projecting radially outwardly beyond said cylinder barrel unit; a reactance assembly surrounding said cylinder barrel unit and comprising a middle section and two end sections separably connected one portions, the pins Journaled m the pistons of one set being independent of the pins jourpistons of one of said sets having independent rolling engagement respectively with said middle track and oneof said end tracks, and the projecting portions of the pins associated with the pistons of the other of said sets having rolling engagement respectively with said middle track and the other of said end tracks, the pins associated with the pistons of one of said sets axially overlapping and being circumferentially interspaced with the pins associated with the pistons of the other of said sets. 20. In a rotary hydraulic pump or motor, a rotatable cylinder barrel unit comprising two sections adapted to be assembled and separated in a direction longitudinally of the axis of rotation of said unit, means providing a mortise joint between said sections for aligning them, and means for maintaining said sections in assembled relation, each section being formed with a set of radial circumferentially deployed cylinders, the two sets o! cylinders being mutually spaced 1ongitudinally of said axis of rotation, the cylinders of one of said sets being circumferentially staggered with respect to the cylinders of the other of said sets; pistons reciprocable in the cylinders of each set respectively and having outer end portions projecting radially outwardly beyond said cylinder barrel unit; a reactance assembly surrounding said cylinder barrel unit and comprising a middle section and two end sections separably connected to said middle section, said middle section being formed with a ange extending radially inwardly between the outer end -portions of the pistons of said two sets and the inner surface of said flange constituting a middle eccentric track, said end sections being formed with similarly eccentric end tracks; and thrust` transmitting pins respectively individually journaled in the outer end portions of said pistons and extending parallel to said axis of rotation and projecting beyond both sides of the respectively associated piston outer end portions, the pins journaled in the pistons of one set being independent of the pins journaled in the pistons said end tracks, and the projecting portions of naled in the pistons of the other set, the projecting portions of the pins associated with the the pins associated with the pistons of the other of said sets having rolling engagement respectively with said middle track and the other of said end tracks.

ELEK K. BENEDEK. 

